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Abstract:

The production method of the coating material comprising the steps of
applying and drying liquid polyurethane (PU) material onto a release
paper in order to form three polyurethane (PU) layers, rolling the
composite layer and separating the release paper to form the composite
coating material for covering the outer shells of electronic devices. The
polyurethane (PU) composite coating material thereby produced comprises
at least a colored surface layer and a substrate layer. The surface of
the composite coating material is colored and has a relief-like pattern,
which can provide users with a better visual or touch effect.

Claims:

1. The production method of composite coating material, comprising the
steps of:(1) applying a first layer of liquid polyurethane (PU) material
onto a surface of a release paper;(2) drying said first polyurethane (PU)
layer;(3) applying a second layer of liquid polyurethane (PU) material on
said first polyurethane (PU) layer;(4) drying said second polyurethane
(PU) layer;(5) applying a third layer of liquid polyurethane (PU)
material on said second polyurethane (PU) layer;(6) drying said third
polyurethane (PU) layer; and(7) rolling said composite layer and
separating said release paper therefrom to form said composite coating
material.

2. The production method of composite coating material of claim 1 wherein
said polyurethane (PU) material making said first layer is of an
arbitrary color

3. The production method of composite coating material of claim 1 wherein
said polyurethane (PU) material making said second layer is added with
foam agent.

4. The production method of composite coating material of claim 1 wherein
said second layer is applied with polyurethane (PU) material at least
twice.

5. The production method of composite coating material, comprising the
steps of:(1) applying a layer of liquid polyurethane (PU) material of wet
type onto a surface of a release carrier substrate;(2) immersing said
polyurethane (PU) layer into water till said polyurethane (PU) layer
solidifies;(3) washing said solidified polyurethane (PU) cloth;(4) drying
said polyurethane (PU) layer; and(5) rolling and grinding said
polyurethane (PU) layer so that said polyurethane (PU) layer can be
separated from said release carrier substrate.

Description:

[0001]The present invention is a divisional patent application of the U.S.
Patent Series No. 11/418,914 assigned and invented by the applicant of
the present invention. Thereby the content of the patent, U.S. Patent
Series No. 11/418,914, is incorporated into the present invention as a
part of the present invention.

[0002]In the present invention, the contents of the claims 11 to 15 in the
original U.S. Patent with Series No. 11/418,914 is selected and claimed
in this application. No other new matter is added.

FIELD OF THE INVENTION

[0003]The present invention relates to coating materials, more
particularly to a composition and the production method of a coating
material whose surface is colored and has a relief-like pattern for
providing users with a better visual or touch effect when coated on the
outer shells of electronic devices.

BACKGROUND OF THE INVENTION

[0004]The outer shells of electronic devices in the market are made of a
material selected from ABS plastics, magnesium alloy, carbon fibers and
titanium alloy. The four materials for making the outer shells have
respectively advantages and disadvantages, and the following is a
comparison.

[0005]ABS is a copolymer made by polymerizing styrene and acrylonitrile in
the presence of polybutadiene, which is properties of heat-resistance and
solvent-resistance better than those of high impact polystyrene (HIPS)
plastics. The ABS materials is further more reflective. Because of the
strong polarity of the CN-group of acrylonitrile, the Polystyrene (PS)
molecular chain is enhanced, thereby causing a impact strength,
stretching strength and surface hardness of the resulted plastic objects
better than .high impact polystyrene (HIPS) plastics.

[0006]The higher the acrylonitrile content of a material is, the better
the heat resistance, the rigidity and the anti-solvent property. Since
the material of high acrylonitrile content is very stable, an object made
of the ABS material has excellent mechanical property and particularly
suitable for making plastic parts by injection molding for engineering
purposes.

[0007]The ABS resin of high brilliance, shock-resistance and capable of
being electroplated is used in home appliances and toys. The ABS of high
fluidity is used in appliances of large size, motorcycle outer shells and
products of thin shells. On the other hand, the ABS of low fluidity is
used in producing slabs and tubes by injection molding, which is realized
in the inner walls of refrigerators, briefcases, tubes and other large
containers. The fire-proof ABS materials are used in making computer
outer shells, computer accessories, electronic devices and business
machines that need to satisfy UL94 standard. The heat-resistant ABS
materials are used in making outer shells of heat-generating appliances,
air blowers, heaters and automobile parts (such as meter panels).

[0008]However, despite high hardness and shock-resistance, ABS materials
are inferior in heat conduction and dissipation compared with magnesium
and titanium alloys. Further, their extension performance is mediocre,
and therefore the extent the their outlooks may vary is limited. Overall,
the outer shells made of ABS are cheap and fast to manufacture, but their
toughness is not tough enough and cannot prevent electromagnetic wave
leakage.

The second type: magnesium alloy

[0009]The earliest use of magnesium alloy is in aerospace industry, in the
year of 1808. Because of toughness, thermal conductivity and being easy
to make modules, magnesium alloy is replacing aluminum steel and plastic
in making electronic devices.

[0010]There many advantages of magnesium alloy as follows. They are: (1)
good shielding effect of electromagnetic interference (because magnesium
alloy is non-magnetic metal); (2) high thermal conductivity, good for
heat dissipation of high-performance CPU; (3) light weight and good
toughness (because the ratio of magnesium to aluminum is 1/3 and to iron
1/4, the rigidity thereof higher than iron and aluminum); (4) high
shock-absorbing property, with a damping capacity 10-25 times aluminum
alloy, 1.5 times zinc alloy; (5) low deformability even it goes through a
large temperature change; and (6) high production rate, because liquid
magnesium alloy will solidify rapidly in a mold.

[0011]Magnesium, being the eighth most abundant element on the earth, has
an almost unlimited supply. Magnesium alloy is traditionally used in
automobile, bicycle and tool parts. Since it is of light weight and high
thermal conductivity, it can be used in 3C products, such as computer
outer shells.

[0012]A single magnesium alloy plate is about 1.0 mm, which is of high
malleability and will succumb to a designed outlook. However, it has a
high thermal conductivity, and it should be careful in handling the heat
radiation during the manufacturing process.

[0013]Further, the casting of objects made of magnesium alloy has a high
fault rate, and secondary processing is usually needed, such as anti-rust
surface treatment and painting, which will largely increase labor cost.

The Third Type: Carbon Fiber

[0014]In future, electronic devices made of carbon-fiber alloys may
replace those made of magnesium alloys, whereby the devices will be
lighter and more portable. Although, the magnesium alloy materials are
currently predominating, they have some problems, such as the definite
method of recycling.

[0015]The flexibility of carbon-fiber alloys can be significantly improved
by the quantity of added carbon fibers to attain a level glass fibers
cannot attain.

[0016]The carbon-fiber coating material can completely attain the
requirement of light weight and be easily provided with surface patterns
of various styles. Further, its toughness is twice of magnesium alloy
(while weights only 80% thereof), and its shielding capability against
electromagnetic waves is also superior.

[0017]However, even a carbon-fiber plate as thin as 1.2 mm, of good
shock-absorbing and anti-erosion properties, a toughness twice of
magnesium alloy, low deformability and especially high thermal
conductivity, its strength being the outer shells of notebook computers
is still mediocre.

The Fourth Type: Titanium Alloy

[0018]Titanium alloys are initially widely used in aerospace industry.
They have the advantages of light weight, high toughness, good
shock-absorbing property, good malleability and good thermal
conductivity. Therefore, titanium alloys are now widely used in daily
life appliances. Because of its properties of heat-resistance and
anti-erosion, artificial bones are made of titanium alloys too.

[0019]A plate of titanium alloy used to form the outer case of a notebook
computer is as thin as 0.5 mm, 50% of that made of magnesium alloy. The
titanium alloy computer case has much better heat radiation property and
good malleability to accommodate various designs. Since the toughness is
three to four times of magnesium alloy, the computer case made of
titanium alloy is the lightest so far.

[0020]However, even with the advantages described above, the computer
cases made of titanium alloys have the disadvantage of relatively fragile
mechanical property due to the HCP crystal structure of titanium alloy.
Therefore, the case cannot be made by die-casting and only by punching.
Further, it can be formed piece by piece, which requires secondary
processing of piece connections and therefore much higher production
cost.

[0021]In summary, the outer cases of electronic devices are made of ABS
plastic, magnesium alloy, carbon fiber and titanium alloy, of which
magnesium and titanium alloys are most popular. The cases made of ABS
plastic are of low production cost, since they can be formed at once by
ejection molding, even there are many reinforcing rip structures and
connection portions thereon. However, the ABS case cannot quite satisfy
the requirement of toughness and shielding against the electromagnetic
wave leakage. On the other hand, the magnesium alloy cases have a high
fault ratio as produced by die-casting. Also, the secondary processing
such as anti-rust surface treatment will cost extra manpower. The
computer cases made of titanium alloys have the disadvantage of
relatively fragile mechanical property due to the HCP crystal structure
of titanium alloy. Therefore, the case cannot be made by die-casting and
only by punching. Further, it can be formed piece by piece, which
requires secondary processing of piece connections and therefore much
higher production cost.

[0022]Moreover, outer shells of electronic devices are usually made of
metallic materials, such as magnesium and titanium alloys. Therefore, the
feeling of touching them is hard and cold. It is also difficult to
produce a relief pattern on a shell for enhancing holding.

[0023]It is less friendly to the environment that the production of
metallic cases such as magnesium alloy needs secondary treatments in
which chemical solvents are extensively used, therefore producing
pollutants to the environment at the same time.

SUMMARY OF THE INVENTION

[0024]The primary objective of the present invention is to provide a
composite coating material and the production method of the same, which
is cheap to manufacture and may have various colors and surface
relief-like patterns. Therefore, the devices coated with the material are
easier to hold and more visually appealing.

[0025]Compared with metallic or carbon-fiber outer shells, the devices
coated by a polyurethane (PU) layer is warm and soft. The surface of the
layer is easier to form a relief pattern, without using the expensive
techniques of erosive carving. Therefore, devices coated by the material
as disclosed by the present invention are easier to hold.

[0026]The present invention is also for solving the restrictions of the
conventional coating materials, such as ABS plastics, magnesium alloy,
carbon fibers and titanium alloy. The following is a brief description of
polyurethane (PU) material.

[0027]The main polyurethane producing reaction is between a diisocyanate
(aromatic and aliphatic types are available) and a polyol, typically a
polyethylene glycol or polyester polyol, in the presence of catalysts and
materials for controlling the cell structure, (surfactants) in the case
of foams. Polyurethane can be made in a variety of densities and
hardnesses by varying the type of monomer(s) used and adding other
substances to modify their characteristics, notably density, or enhance
their performance. Other additives can be used to improve the fire
performance, stability in difficult chemical environments and other
properties of the polyurethane products.

[0028]The properties of the polyurethane resin are determined mainly by
the choice of polyol, which produces soft segments therein. There are
further hard segments reduced by Diisocyanate , resulting in phase
separation and the island-like crystallization appearing in the PU
material. Thereby, the PU material at room temperature will exhibit the
phenomenon of physical crosslink, which will enhance its mechanical
property, despite a molecular weight of tens of thousands.

[0029]Polyurethane (PU) is used to make soft and hard foamed plastic
materials, structural materials, flexible artificial leathers and other
thermosetting flexible materials, which can be applied in the following
areas:

[0034]E. insulating material industry for making parts such as
refrigerators, freezer containers, water-proof materials applied on house
roofs and gas pipelines;

[0035]F. soft foamed plastic industry for making sofas.

[0036]The production method of the present invention includes adding dye
agent into the liquid PU material to achieve a desired color at the outer
surface. A release paper is also used for providing a relief pattern on
the composite material. Since PU material feels warm, the coating
material thereby produced is not only friendly to touch but also visually
appealing. Further, the sponge-like inner layer of the coating material
makes the present invention thicker, more water-resistant and
noise-reducing.

[0037]To summarize, the present invention is to provide a PU coating
material and the production method of the same, which is cheap to
manufacture and may have various colors and surface relief-like patterns.
In replacement of the current coating materials such as ABS and metallic
alloys, devices coated by the present invention are easier to hold and
more visually appealing.

[0038]As shown in FIG. 1, the structure of the present invention comprises
a PU surface layer 120 having a selective color and relief-like pattern,
a PU structure layer 130 which can be sponge-like or foam-free and a
substrate layer 140.

[0039]Referring to FIG. 2, the second preferred embodiment of the present
invention comprises a polyurethane (PU) surface layer having a colored
surface pattern 120, a sponge-like structure layer 131 made of
polyurethane (PU) material with foam agent and a substrate layer 140, as
shown in FIG. 2. The third preferred embodiment of the present invention
comprises a colored polyurethane (PU) surface layer 120 with a pattern, a
polyurethane (PU) foam-free structure layer 132, a sponge-like structure
layer 131 and a substrate layer 140, as shown in FIG. 3. The foam-free
structure layer 132 is right above the substrate layer 140. The fourth
preferred embodiment of the present invention comprises a colored
polyurethane (PU) surface layer 120 with a pattern, a polyurethane (PU)
foam-free structure layer 132, a sponge-like structure layer 131 and a
substrate layer 140, as shown in FIG. 4. The fifth preferred embodiment
of the present invention comprises a polyurethane (PU) surface layer 120
and a substrate layer 140, as shown in FIG. 5.

BRIEF DESCRIPTION OF THE DRAWINGS

[0040]FIG. 1 is a cross-sectional view of the first preferred embodiment
of the present invention.

[0041]FIG. 2 is a cross-sectional view of the second preferred embodiment
of the present invention.

[0042]FIG. 3 is a cross-sectional view of the third preferred embodiment
of the present invention.

[0043]FIG. 4 is a cross-sectional view of the fourth preferred embodiment
of the present invention.

[0044]FIG. 5 is a cross-sectional view of the fifth preferred embodiment
of the present invention.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0045]The various objects and advantages of the present invention will be
more readily understood from the following detailed description when read
in conjunction with the appended drawings.

The First Preferred Embodiment

[0046]A release paper with a surface pattern is applied with a colored
polyurethane (PU) layer and is then dried. When the release paper covered
by the polyurethane (PU) layer is dry, another polyurethane (PU) layer is
applied and dried to form a structure layer 130. A third polyurethane
(PU) layer is applied to form a substrate layer 140. The composite
structure on the release paper goes through processes of drying, rolling
and forming to further form a surface layer 120 after the release paper
is taken away. Thereby, a polyurethane (PU) layer having a colored
surface pattern for covering the outer surface of an electronic device is
formed, as shown in FIG. 1. The thickness of the PU layer is 0.5 mm. The
second PU layer has a pore ratio of 0%. The hardness of the composite PU
layer is ShoreA: 60.

The Second Preferred Embodiment

[0047]A release paper with a surface pattern is applied with a colored
polyurethane (PU) layer and is then dried. When the release paper covered
by the polyurethane (PU) layer is dry, another polyurethane (PU) layer
added with foam agent is applied thereon and dried to form a sponge-like
structure layer 131. A third polyurethane (PU) layer is applied to form a
substrate layer 140. The composite structure on the release paper goes
through processes of drying, rolling and forming to further form a
surface layer 120 after the release paper is taken away. Thereby, a
polyurethane (PU) layer having a colored surface pattern for covering the
outer surface of an electronic device is formed, as shown in FIG. 2. The
thickness of the PU layer is 0.7 mm. The second PU layer has a pore ratio
of 40%. The hardness of the composite PU layer is ShoreA: 30.

The Third Preferred Embodiment

[0048]A release paper with a surface pattern is applied with a colored
polyurethane (PU) layer and is then dried. When the release paper covered
by the polyurethane (PU) layer is dry, another polyurethane (PU) layer is
applied thereon and dried to form a foam-free structure layer 132. A
third polyurethane (PU) layer, added with foam agent, is then applied to
form sponge-like structure layer 131. It is then applied with a final
polyurethane (PU) layer to form a substrate layer 140. The composite
structure on the release paper goes through processes of drying, rolling
and forming to further form a surface layer 120 after the release paper
is taken away. Thereby, a composite polyurethane (PU) layer having a
colored surface pattern for covering the outer surface of an electronic
device is formed, as shown in FIG. 3, wherein the middle structure layer
130 consists of the sponge-like structure layer 131 and the foam-free
structure layer 132 adjacent to the surface layer 120. The thickness of
the PU layer is 0.6 mm. The second PU layer has a pore ratio of 0%. The
hardness of the composite PU layer is ShoreA: 40.

The Fourth Preferred Embodiment

[0049]A release paper with a surface pattern is applied with a colored
polyurethane (PU) layer and is then dried. When the release paper covered
by the polyurethane (PU) layer is dry, another polyurethane (PU) layer,
added with foam agent, is applied thereon and dried to form a sponge-like
structure layer 131. A third polyurethane (PU) layer is then applied to
form foam-free structure layer 132. It is then applied with a final
polyurethane (PU) layer to form a substrate layer 140. The composite
structure on the release paper goes through processes of drying, rolling
and forming to further form a surface layer 120 after the release paper
is taken away. Thereby, a composite polyurethane (PU) layer having a
colored surface pattern for covering the outer surface of an electronic
device is formed, as shown in FIG. 3, wherein the middle structure layer
130 consists of the foam-free structure layer 132 and the sponge-like
structure layer 131 adjacent to the surface layer 120. The thickness of
the PU layer is 0.6 mm. The sponge-like PU structure layer 131 has a pore
ratio of 70%. The foam-free PU structure layer 132 has a pore ratio of
0%. The hardness of the composite PU layer is ShoreA: 35.

The Fifth Preferred Embodiment

[0050]A release cloth with a surface pattern is applied with a
polyurethane (PU) layer of wet type and is immersed into water till the
PU layer is condensed. The PU layer is then washed (by water), dried,
rolled, surface-treated and then removed from the release cloth, forming
a fur-like skin for covering the outer surface of an electronic device.
The thickness of the PU layer is 0.4 mm. The PU structure layer has a
pore ratio of 30%. The hardness of the composite PU layer is ShoreA: 15.

[0051]The present invention is thus described, and it will be obvious that
the same may be varied in many ways. Such variations are not to be
regarded as a departure from the spirit and scope of the present
invention, and all such modifications as would be obvious to one skilled
in the art are intended to be included within the scope of the following
claims.

Patent applications by Chung-Ching Feng, Kaohsiung City TW

Patent applications by I-Peng Yao, Kaohsiung City TW

Patent applications by Kai-Feng Kang, Kaohsiung County TW

Patent applications by Ko-Feng Wang, Kaohsiung County TW

Patent applications by Pei-Huo Huang, Kaohsiung City TW

Patent applications by Yong-Song Lin, Kaohsiung County TW

Patent applications in class WITH WINDING, BALLING, ROLLING, OR COILING

Patent applications in all subclasses WITH WINDING, BALLING, ROLLING, OR COILING